l. Field of the Invention
The invention relates to a combination flow shut off valve and well condition sensing device for downhole installation in a well conduit immediate to a producing zone.
2. Description of the Prior Art.
In the completion of oil or gas wells, it is essential that accurate measurements be taken of various parameters involved in the production zone, such as fluid pressure and temperature. Experience has shown that more reliable measurements are obtained when the condition sensing device is positioned closely adjacent the producing zone and upward flow of produced fluids is entirely shut off. Additionally, certain important operating parameters are best determined by measurements taken first after a flow shut off, then re-opening the shut off valve to permit fluid flow, then shutting off the flow and taking an additional set of measurements.
Downhole shut off valves have heretofore been utilized but have been characterized by relatively complex structures requiring a plurality of trips into the well to install and a plurality of trips to remove from the well at the completion of the tests. There is, therefore, a distinct need for a downhole shut off valve operable in conjunction with a condition sensing device which can be installed in a single trip of an auxiliary conduit into the well. Where the sensing device is electric, it would be highly advantageous to accomplish the run-in and flow shut off with an electric wire line.